Air Quality Conformity Determination

Following passage of the federal Clean Air Act Amendments in 1990, the Salem-Keizer area was designated as a non-attainment area to the carbon monoxide (CO) and 1-hour ozone (O₃) national ambient air quality standards (NAAQS).  However, monitoring data since that time has shown that pollutant levels are decreasing.  CO levels have steadily declined and continue to be far below the NAAQS.  

Carbon Monoxide Status

Previously, the CO monitor for the SKATS region was located at Market Street and Lancaster Drive.  The CO monitor had been located there in the past to ensure that measurements were being made in the location of highest CO concentrations prior to a re-designation effort.  No violations of the carbon monoxide standard were recorded between 1984 and 2003, and the last exceedance was in 1993.  Based on this history of clean air, the Oregon Department of Environmental Quality (DEQ) removed the CO monitor in 2006 and developed a Carbon Monoxide Limited Maintenance Plan for the SKATS region, which was submitted to EPA in 2007 and went into effect March 2, 2009.  As an area with a limited maintenance plan, SKATS is no longer required perform emissions analysis for CO but still must demonstrate conformity as discussed below.

Ozone Status

On April 30, 2004, EPA formally designated the entire state of Oregon “attainment” for the new 8-hour ozone NAAQS.  

Transportation Conformity for the SKATS area

According to federal rules, while areas with approved limited maintenance plans are not required to perform a regional emission analysis, they are required to demonstrate conformity of the transportation plans as stated in 40 CFR part 93, subpart A. For each adopted Regional Transportation Systems Plan (RTSP) and Transportation Improvement Program (TIP) a separate Air Quality Conformity Determination (AQCD) must be completed.